An account of birding adventures in New Brunswick; occasional posts about other wild creatures, art and ethics.

Thursday, June 30, 2016

Snapping Turtle

Our Largest Turtle

The Snapping Turtle (Chelydra serpentina) is our largest turtle, with the exception of sea turtles. They range from 12 to 18 inches long (30 - 45 cm) and weigh up to 30 pounds (66 kg).

Snapping Turtle (torontozoo.com)

The Snapping Turtle is easy to distinguish from our other native New Brunswick turtles by its size and morphology. It is larger. The Painted Turtle is often around 8 to 10 inches (12-25 cm) and the wood turtle is about the same size (although much rarer at this point). The Snapping Turtle has a longer tail with a saw-toothed upper ridge and a much smaller plastron (bottom plate). The plastron, in fact, looks incomplete. It does not cover the entire ventral surface of the turtle like it does in the Painted and Wood Turtles.

Snapping Turtles live in permanent fresh water ponds, lakes and rivers. They feed on fish, invertebrates, amphibians, pond vegetation and sometimes young waterfowl. Their range covers southern Canada east of the Rocky Mountains and southeastward through the United States to Florida.

Snapping Turtles Laying Eggs [E Mills Photo]

Snapping Turtles usually travel long distances to find suitable sand in which to lay their eggs. Shown above is a sand dune along Grand Lake where Snapping Turtles come annually to lay eggs. Eggs are usually laid in late spring or early summer. The female digs a deep hole into which she slides her body. After 25 to 80 eggs are laid, she covers them carefully before returning to the water. The incubation period ranges from 9 to 18 weeks. In colder temperatures the hatchlings spend the winter in the nest.

Snapping Turtle Eggs [Internet Photo]

The female Snapping Turtle has an unusual ability to store sperm from a mating for several seasons, using it as necessary. This is a useful adaptive feature if the population is low and males are hard to find. The shells on turtle eggs are leathery, not hard like bird egg shells. This makes them withstand the pressure of the sand covering them.

Snapping Turtle Laying Eggs [E Mills Photo]

Snapping Turtles are famous for their bites. If you didn't know that, pay careful attention! They can bite your finger off! They can also whip their head around and bite you much faster than you think. Their necks are much longer and more flexible than in other turtles. Picking one up by the sides of the carapace (shell) is definitely not advised. They can bite you there. NEVER, pick one up by the tail. That can injure the tail and spinal cord. The proper way to pick one up is to cover it with a tarp or blanket. Lay the blanket flat and when the turtle crawls on it, wrap it around the turtle and then move it off the road or out of harms way. Another common mistake is to entice the turtle to bite a stick and then drag the turtle across the road. This is harmful to the turtle, scraping and abrading the skin on the legs and underside. If all else fails, it is possible to pick one up safely by the carapace by placing the hands around the carapace at the level of the hind legs. Good luck!

Snapping Turtles are very cold-tolerant. Some individuals remain active under the ice all winter. Most hibernate in the mud at the bottom of ponds. They can go for up to 6 months without breathing air. They have a special system for respiration called extra-pulmonary respiration. They stick their heads above the mud at the pond bottom periodically and absorb oxygen from the water through the membranes lining their mouths and throats. If this is not enough, they breathe anaerobically by using stored fats and sugars.

As you can tell, these are amazing creatures. They have adapted over eons to survive in harsh and varied environments. We are lucky to be able to observe them in our province. Watch out for them on the highways as they make their way to sandy areas to lay eggs or are returning to favourite pond.